There is known from International Patent Application No. WO/9744715 a time-setting device for a watch. This device includes a rotating bezel placed on the exterior of the case. This bezel has a contrate toothing which co-operates with a pinion carried by a control stem provided with a crown. Depending upon whether the crown is disposed in a first or in a second pulled out position, rotational movement of the bezel causes the simultaneous rotation of the control stem and allows, for example, the current time display or an alarm to be set.
The device briefly described hereinbefore allows the various functions of the watch to be more easily adjusted. In particular, one need only pull out the control stem into the desired position and then rotate the bezel in order to carry out the setting Since the rotating bezel is placed on the top of the watchcase, it is very easily accessible, which allows the person wearing said watch to carry out adjustments without removing the watch from his wrist.
This device also has the advantage of providing a watch having pure lines and shapes. Indeed, when the control stem is not in a pulled out position, its crown is embedded in the middle part of the watch, such that the middle part has a smooth and practically continuous surface, free of any protruding portions. This is of course not the case of conventional watches, whose crown generally projects from the side of the middle part.
One drawback of the type of device concerned here lies however in the fact that it occupies a considerable amount of space. Indeed, the bezel extends over the entire external periphery of the watch, which means that sufficient place has to be provided to mount it on the watch case. More often than not, this space is made available by reducing the size of the crystal and the dial, which is detrimental to the legibility of the information displayed by the watch. This problem arises very acutely when the watch has a date disc displaying the day of the month. In a usual embodiment, this date disc is formed by a ring with an inner toothing, whose external diameter is substantially equal to that of the watch movement. It is generally driven by a resilient finger piece carried by a driving wheel that is itself linked to the hour wheel. The finger piece acts once a day on a tooth of the date disc to move it by one thirty-first of a revolution.
If, because of the presence of the rotating bezel, the diameter of the date disc has to be reduced, this will affect the legibility of the figures indicating the dates affixed to the disc. In order to overcome this problem, a known solution consists in providing two date discs concentrically arranged with respect to each other. In this embodiment, the external ring carries figures indicating the units of the day of the month, whereas the figures indicating the tens of the date are affixed to the inner ring. The fact of using two rings of large diameter means that larger sized and thus more easily legible figures indicating the units and the tens of the day of the month can be added to the rings. It will be understood however that such a device is complex and thus has a higher cost price.
The object of the present invention is to overcome the aforementioned problems in addition to others by proposing a reliable and compact device particularly for setting the time of a date watch.